This invention relates to the field of blowers for equipment enclosures. In particular, this invention is directed to the elimination of reverse airflow through blowers.
Cabinetry or enclosures for heat generating equipment may contain one or more blowers for active or forced air cooling. The blower displaces the air within the enclosure volume with cooler air external from the enclosure volume. The blower acts as a pump to transfer air between the two environments. Air pumped from the interior by the blower is replaced with air external to the enclosure through the vents or ports of the cabinet or enclosure. Alternatively, air pumped from the exterior of the enclosure into the enclosure displaces the air in the enclosure through the vents. Heat generating components requiring forced air cooling may overheat resulting in erratic, unpredictable behavior or a shortened lifespan among other maladies if there is no active cooling.
Blower systems may incorporate multiple blowers for redundancy or to achieve a specific airflow pattern in order to ensure adequate cooling. The failure of a single blower, however, creates a new source for air via its exhaust or intake vent. As a result, the airflow patterns within the enclosure may be sufficiently disrupted which prevents adequate cooling or which significantly decreases the efficiency of redundant blower systems.
Baffles may be used to prevent reverse airflow. Baffles have a number of members that pivot to enable opening and closing the baffle. Passive baffles typically rely on gravity or springs to keep the baffles closed when the blower is off. During normal operation, passive baffles rely upon the pressure developed by the blower to open. Active baffles require power and airflow detecting control circuitry at least to open the baffles. These passive or active baffle designs tend to introduce complexity into the manufacturing and assembly of the equipment enclosures. The active baffles undesirably require additional electrical connections and introduce additional points of failure due to the electrical components. The passive baffles additionally tend to significantly impede the flow of air through the blower exhaust thus imposing greater performance requirements on the blowers.
In view of limitations of known systems and methods, methods and apparatus for assembling a blower having a one-way valve are provided.
A method of assembling a blower includes the step of providing a blower housing having at least one channel. A flexible sheet having at least one flap is attached to the blower housing such that the flap overlaps the channel to form a one-way valve. The flexible sheet may include mounting features such as holes to facilitate assembly. For example, in one embodiment, the flexible sheet is pressed onto a plurality of pegs residing on the blower housing such that the holes receive the pegs. In another embodiment, the flexible sheet is pressed onto a plurality of pegs residing on an exhaust cover that is subsequently attached to the blower housing.
A blower apparatus includes a blower housing having a plurality of channels at an exhaust port. A flexible sheet having a plurality of flaps is coupled to the blower housing such that each flap overlaps at least one channel to form a one-way valve.
Other features and advantages of the present invention will be apparent from the accompanying drawings and from the detailed description that follows below.